The present invention concerns a gas laser, in particular an ion laser. In such a laser a plasma discharge in which the atoms or ions of the gas are excited and caused to emit light burns in a gas-filled discharge tube arranged between a cathode and an anode.
The discharge tube of an ion laser becomes very hot in operation, which, among other things, limits the power-handling capacity and life of the laser.
From U.S. Pat. No. 4,378,600 an ion laser is known in which the discharge tube is cooled. In that laser, the discharge tube is supported with the aid of several disks within a gas-filled support tube which is surrounded by an outer tube with a space between. A coolant flows through the outer space formed by these two tubes. The support disks are made of copper and transport the heat by heat conduction from the discharge tube to the support tube. The coolant which flows around the support tube removes the heat from it.
This known ion laser has the disadvantage that the cooling of the discharge tube is not produced rapidly and effectively by heat conduction via the support disks and support tube, so that the temperature of the discharge tube still reaches rather high values.
The object of the present invention is to provide a gas laser, in particular an ion laser, which is characterized by a long life and good reproducibility of the radiation produced.